Acute Microbial Protease Supplementation Increases Net Postprandial Plasma Amino Acid Concentrations After Pea Protein Ingestion in Healthy Adults: A Randomized, Double-Blind, Placebo-Controlled Trial

Kevin J M Paulussen; Andrew T Askow; Max T Deutz; Colleen F McKenna; Sean M Garvey; Justin L Guice; Richard M Kesler; Takeshi M Barnes; Kelly M Tinker; Scott A Paluska; Alexander V Ulanov; Laura L Bauer; Ryan N Dilger; Nicholas A Burd

doi:10.1016/j.tjnut.2024.03.009

Acute Microbial Protease Supplementation Increases Net Postprandial Plasma Amino Acid Concentrations After Pea Protein Ingestion in Healthy Adults: A Randomized, Double-Blind, Placebo-Controlled Trial

J Nutr. 2024 Mar 11:S0022-3166(24)00158-5. doi: 10.1016/j.tjnut.2024.03.009. Online ahead of print.

Affiliations

¹ Department of Health and Kinesiology, University of Illinois Urbana-Champaign, Urbana, IL, United States.
² Division of Nutritional Sciences, University of Illinois Urbana-Champaign, Urbana, IL, United States.
³ Department of Research and Development, BIO-CAT, Inc., Troy, VA, United States.
⁴ Department of Health and Kinesiology, University of Illinois Urbana-Champaign, Urbana, IL, United States; Illinois Fire Service Institute, University of Illinois Urbana-Champaign, Urbana, IL, United States.
⁵ Roy J. Carver Biotechnology Center, University of Illinois Urbana-Champaign, Urbana, IL, States.
⁶ Department of Animal Sciences, University of Illinois Urbana-Champaign, Urbana, IL, United States.
⁷ Division of Nutritional Sciences, University of Illinois Urbana-Champaign, Urbana, IL, United States; Department of Animal Sciences, University of Illinois Urbana-Champaign, Urbana, IL, United States; Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, IL, United States.
⁸ Department of Health and Kinesiology, University of Illinois Urbana-Champaign, Urbana, IL, United States; Division of Nutritional Sciences, University of Illinois Urbana-Champaign, Urbana, IL, United States. Electronic address: naburd@illinois.edu.

PMID: 38467279
DOI: 10.1016/j.tjnut.2024.03.009

Abstract

Background: Digestibility is a primary factor in determining the quality of dietary protein. Microbial protease supplementation may be a strategy for improving protein digestion and subsequent postprandial plasma amino acid availability.

Objectives: To assess the effect of co-ingesting a microbial protease mixture with pea protein on postprandial plasma amino acid concentrations.

Design: A mixture of 3 microbial protease preparations (P3) was tested for proteolytic efficacy in an in vitro static simulation of gastrointestinal digestion. Subsequently, in a randomized, double-blind, placebo-controlled crossover trial, 24 healthy adults (27 ± 4 y; 12 females, 12 males) ingested 25 g pea protein isolate (20 g protein, 2.2 g fat) with either P3 or maltodextrin placebo (PLA). Blood samples were collected at baseline and throughout a 0‒5 h postprandial period and both the early (0-2 h) iAUC and total (0-5 h) iAUC were examined.

Results: Plasma glucose concentrations decreased in both conditions (P < 0.001), with higher concentrations after P3 ingestion compared with PLA (P < 0.001). Plasma insulin concentrations increased for both conditions (P < 0.001) with no difference between conditions (P = 0.331). Plasma total amino acid (TAA) concentrations increased over time (P < 0.001) with higher concentrations observed for P3 compared with PLA (P = 0.010) during the 0‒5 h period. There was a trend for elevated essential amino acid (EAA) concentrations for P3 compared with PLA (P = 0.099) during the 0‒5 h postprandial period but not for leucine (P = 0.282) or branched-chain amino acids (BCAA, P = 0.410). The early net exposure (0‒2 h iAUC) to amino acids (leucine, BCAA, EAA, and TAA) was higher for P3 compared with PLA (all, P < 0.05).

Conclusions: Microbial protease co-ingestion increases plasma TAA concentrations (0-5 h) and leucine, BCAA, EAA, and TAA availability in the early postprandial period (0‒2 h) compared with ingesting pea protein with placebo in healthy adults.

Keywords: anabolism; leucine; plant-based protein; protein foods.